New York Natural Heritage Program
Broad-tailed Shadowdragon
Neurocordulia michaeli Brunelle, 2000

Threats [-]
Because the entire New York population occurs on only a short segment of the upper Delaware River, any activities which degrade these sensitive habitats might threaten this species. The most important likely negative impacts would come from changes in water temperature or the natural hydrology such as water removals, the operations of upstream dams (Donnelly 1993), increases in the sediment load or associated stream changes in dissolved oxygen content, direct effects of pesticides, and chemical contamination by runoff of agricultural or other discharge.

Conservation Strategies and Management Practices [-]
The effects on this species of managing the upper Delaware River as a coldwater trout sport fishery (via hypolimnial water releases from the NYC water supply dams) should be investigated. In addition, dense stands of invasive Japanese Knotweed (Fallopia japonica) along the riverbanks may alter ecological proccesses along this reach of the river.

Research Needs [-]
This species was first documented in New York on the upper Delaware River in 2008, 2009 during the NYDDS. It may be more common and widespread than current records indicate, but owing to its cryptic, crepuscular behavior as well as its larval similarity to Neurocordulia yamaskanensis, it may be under-reported. The status of the regional range disjunction is not known, but the species was not found during a newly completed multi-year odonate Atlas in New Hampshire.